In-Ear MonitorOverreview

KZ ZSN Pro X

The famous $20 hybrid whose 5 kHz peak splits the people who listen to it.

44 sourcesUpdated
$22Typical US price

Score aggregates reviewer opinions across topics.

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KZ ZSN Pro X

The short version

What to know.

A two-driver hybrid at about $22 with a V-shaped tuning: a full, warm bass, a dip around 1 kHz and a late, strong peak near 5 kHz, with more upper treble than the common targets. Sources broadly agree the bass is punchy and well controlled, that voices sit back in the mix, and that the stage is wide for the price though not deep. Most find the shell comfortable, and reviewers praise the build, while buyer reviews carry more durability complaints than the reviews do. Opinion splits on the treble (about two-thirds of the sources that describe it, by weight, find it harsh or tiring; a third hear it as bright but fine), on whether the tuning as a whole is balanced or aggressive, and on value now that newer rivals cost the same. Measurement rigs show no consistent difference from the older ZSN Pro.

About this product

The 2020 two-driver ZSN Pro X — not the earlier ZSN or ZSN Pro, the later ZSN Pro 2, or the five-driver ZS10 Pro X. Sold with or without an inline mic; the USB-C cable version some stores list is not what is described here.

The ZSN Pro X is the third version of KZ's two-driver ZSN: a 10 mm dynamic driver for the bass and midrange and a single balanced armature for the treble, in a clear resin shell with a metal faceplate and a detachable two-pin cable. It arrived in mid-2020 and still sells for a little over twenty dollars.

It is also one of the best-known cheap earphones there is, as much through YouTube and Amazon as through audio forums, and that fame is why it gets argued about. Buyers who came for an inexpensive upgrade tend to be delighted. Enthusiasts tend to treat it as the example of KZ's old house sound, with plenty of bass and a hard, bright edge on top.

A good fit for

  • A first step up from bundled or supermarket earbuds on a small budget
  • Listeners who like an energetic sound with strong bass and a bright, crisp top end
  • Electronic, hip-hop, pop and rock more than acoustic or vocal-led music
  • Gaming and calls: GearLab rates the mic version highly for call quality
  • People happy to use an equaliser, which owners say tames the treble

Think twice if

  • You are sensitive to treble or sibilance; this is the complaint that comes up most
  • You want natural, forward vocals or a neutral tuning
  • You already own a ZSN Pro; measurements and several reviewers find no real difference
  • You have small ears, or want something that stays put during exercise
  • You plan to plug into a noisy laptop or motherboard output, where its sensitivity makes hiss audible
  • You expect accessories; the box holds the earphones, a cable and a few tips

The reviewer consensus

Agreement &
disagreement.

3 / 11topics divide opinion
bassmidssoundstageimagingdetailcomfortisolationbuildtrebletonalityvalue
8 Mostly agree3 Divided opinions

Common ground7

  • It is a V-shaped tuning: boosted bass, voices set back, and a bright upper midrange and treble.
  • The bass is punchy and well controlled for the price, and is the part of the sound most sources like best.
  • The peak sits late, near 5 kHz; the measurement rigs and SoundGuys' own lab agree on that.

Points of contention5

  • The treble. About two-thirds of sources by weight find it sibilant or fatiguing; about a third hear it as bright but fine. The 5 kHz peak is real on every graph, so the split is in ears and tolerance, not in the earphone.
  • The tuning as a whole. The lab outlets and most buyers call it balanced or enjoyably lively; enthusiast reviewers call it aggressive and metallic. They are judging the same curve against different targets.
  • Value. Most still call it one of the better buys near $22; a sizeable minority say newer earphones at the same price are smoother and that this one adds nothing over the ZSN Pro.

A closer listen.

11 topics · 3 divided
Left: criticalRight: positiveTighter lines: more agreement

Bass

Leans positiveMostly agree
Reviewer sentiment21 supporting sources
CriticalNeutralPositive

Band: opinion spread · Dot: weighted average

The best-liked part of the sound. Most sources describe a punchy, fairly quick bass that reaches deep and stays out of the way of the midrange; a few hear some looseness or warmth bleeding upward from the mid-bass. How much sub-bass there is depends on who is listening: the two lab outlets and one Head-Fi reviewer find the very lowest notes modest.

“The KZ ZSN Pro X offer a crisp, punchy, and well extended low-end which I find inviting.”

Jürgen Kraus, audioreviews.org

“Mid-bass is pushed forward and is still a bit loose at times with some bleed into the mids providing a bit of warmth in an overall bright signature.”

wiljen, Audiofool Reviews

“The bass is clear, fresh, and clean in most mixes and never sounds muddled.”

GearLab

Measured

Across sixteen measurement rigs the 20–40 Hz region sits about 9 dB above the 500 Hz level, level with the Harman in-ear target, and the 80–300 Hz mid-bass about 3.5 dB above that target.

vs. listeners — GearLab and SoundGuys both describe the lowest bass as modest and one Head-Fi reviewer hears no rumble, while the rigs show a full sub-bass shelf. A measurement coupler always seals; a vented shell in a real ear may not, and GearLab's testers found the earpieces easy to dislodge. Two rigs published one channel reading 6 to 18 dB lower in the bass than the other, which is what a lost seal looks like.

Link to this topic

The hardware

Specifications.

Checked

Design

Type
In-ear monitor
Drivers
1 × 10 mm dynamic (dual magnetic) + 1 × balanced armature (30095)1DD + 1BA
Housing
zinc alloy, resin

Electrical

Impedance
25 Ω
Sensitivity
112 dB/mW≈ 128 dB/V
Frequency response
7 Hz – 40 kHz

Connection

Cable
Detachable, 1.25 m
Connector
2-pin
Plugs supplied
3.5 mm

Physical

Released
2020

Sold with or without an inline microphone. Manufacturer-published figures, not measurements · from kz-audio.com, linsoul.com.

Follow the evidence

Sources 44

1–6 of 44 sources

Read with context

Limitations & method.

As of

What to keep in mind 7

  1. This is a read of where opinion stood in November 2026 on an earphone released in 2020. Most of the detailed reviews date from 2020 to 2022, and the budget field has moved a long way since; later comparisons with newer models are less kind than the early reviews.

  2. How the treble lands is personal. The peak sits around 5 kHz and higher, where ear shape, insertion depth and ear tips change what reaches the eardrum, and listeners differ a great deal in how much they tolerate there.

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